Minimum-joint electrified rail system

ABSTRACT

A composite minimum-joint electrified rail is constructed by combining a non-conductive support rail divided into easily installed segments with a continuous conductive rail that mounts on the support rail and spans any number of support rail segments. The conductive rail may be attached to the non-conductive rail by a tongue and groove arrangement. Multiple conductive rails or strips may be attached to different portions of the same support rail. In addition spring clips are shown for attaching the support rail to railroad ties or roadbed, and fish plates are shown for attaching abutted support rails.

FIELD OF THE INVENTION

This invention relates to electrified rails for a railroad. While theinvention has applicability to any scale or type of railroad, it isparticularly useful in scale model railroads.

BACKGROUND OF THE INVENTION

A long standing problem in electrified rails in railroads andparticularlty in scale model railroads has been how to provide goodelectrical continuity the full length of the track while segmenting thetrack into easily installed sections. The electrical continuity betweenthe rail sections in model railroads has been poor.

Typically, the entire rail in a section was made of a conductivematerial such as brass or aluminum. Abutting sections of rails wereconnected physcially and electrically by conductive clips that slid overthe foot of the "I" cross-sectional shape of both rails at the abuttingjoint.

The conductivity of these clip connections between rails was dependenton the tightness of the clip as it gripped the abutting rail sections.Inevitably, these clips would make poorer electrical connections as thetrack was used. The result was that electric engines drawing power fromthe track would lose electrical power in certain track sections or wouldreceive less power the longer the distance from the electrical powersource to the position of the electric engine drawing power from thetrack. Some solutions for this problem in the past have included tracksections that have conductive rails with male/female couplings at theabutment between rail sections. In at least one case, U.S. Pat. No.3,583,631, the rail body was non-conductive and was covered byconductive channel member having couplings to connect abutting sectionsor rails. Another solution shown in U.S. Pat. No. 2,084,322 also usestrack sections with non-conductive rails covered by conductive channelsfitted over the non-conductive rail. In this solution, abutting sectionsof rails are electrically connected by channel clips that fit over theconductive channels at the abutment joint. Both of these solutions aredependent on a tight fit at the coupling between rail sections toprovide good electrical conductivity between abutting rails.

SUMMARY OF THE INVENTION

The electrical continuity problem in sectional rails has been solved byfabricating a composite minimum-joint conductive rail which effectivelyeliminates the electrical discontinuity across joints between abuttingrail sections. This composite minimum-joint conductive rail comprises asectional non-conductive support rail and a minimum-joint conductiverail member that slideably engages the surface of the support rail andspans the abutment joints between rail sections. An electro-motivedevice riding on the conductive rail and drawing power from it sees noelectrical discontinuity across support rail abutment joints. Theconductive rail member may be of any length, depending on the length oftrack to be electrically powered. The conductive rail is fabricated fromcopper, aluminum, nickel or other conductive materials and is flexiblefor ease of installation. It gains its physical strength from thesectional non-conductive support rails.

In one aspect of the invention the surface of the non-conductive railthat is to be electrified is shaped to receive the conductive member.After the non-conductive support rail slideably engages the conductiverail, it the support rail serves to guide the flexible conductive memberto a similar receiving and guiding means on an abutting support rail.

In another aspect of the invention the length of track may beelectrically subdivided into electrical blocks by using conductive railmembers whose length corresponds to the electrical block and byseparating the ends of the conductive rail members with short insulativerail members that slideably engage the support rails in the same manneras the conductive rail member. The length of electrical blocks iscompletely independent of the support rail abutment joints.

The support rail may receive multiple conductive rails, members orstrips. The conductive strips may share the same surface of the supportrail or may be on different surfaces of the support rail.

The conductive rails or strips mate with receiving and guiding means onthe support rail in a number of ways. There may be grooves in thesupport rail and matching beads on the conductive strips that snap intosuch grooves. The conductive strip may have beveled edges that snapunder matching counter-beveled edges on the top surface of the supportrail.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows a preferred embodiment of the minimum-joint conductiverail.

FIGS. 2A, 2B and 2C show a fish plate for connecting abutting supportrails and for compressing the support rail to grip the conductive rail.

FIG. 3A shows a spring-loaded clip for mounting the support rail oninterconnecting ties.

FIG. 3B shows a support rail with two minimum-joint conductive strips,one for providing power to the vehicle and one for providing controlsignals.

FIG. 4A shows a conductive support rail having insulating layers toinsulate the support rail from the minimum-joint conductive strips.

FIGS. 4B and 4C show a preferred embodiment for rail clip for mountingthe rail on ties or roadbed.

FIG. 5 shows a double cylindrical groove and matching bead for attachingthe conductive rail to the non-conductive support rail.

FIG. 6 shows a nonconductive support rail with a dovetail top surface toreceive a matching dovetail shaped conductive member.

FIG. 7 shows a non-conductive support rail carrying two conductivestrips with dovetail beads.

FIG. 8 is the bottom view of a conductive rail with beads at spacedintervals.

FIG. 9 shows a mono-rail embodiment where the support rail carries twominimum-joint conductive rails.

FIG. 10 shows a hanging mono-rail embodiment where the minimum-jointconductive strips are attached to vertical portion of the I-beam.

DETAILED DESCRIPTION OF THE INVENTION

A preferred embodiment of the invention is shown in FIG. 1. Support rail10 is made of electrically non-conductive or insulative material such aspoly-carbonate materials, carbon fibers, ceramics, or combinationsthereof. Any insulative material that has sufficient structural strengthto support a vehicle on the rail may be used. The top of the supportrail 10 contains a notch 12 that runs the length of rail 10. In thepreferred embodiment, notch 12 is a dovetail groove. This dovetailgroove is designed to receive the dovetail bead 14 of a minimum-jointconductive rail 16 on top of support rail 10.

Support rails 10 are abutted end-to-end to form any desired length ofrail in a track system. In FIG. 1, support rail 10 is joined to abuttingsupport rail 18 at joint 22 by fish plate 20 and a matching counterpartfish plate (not shown) on the other side of rails 10 and 18. In a modelrailroad implementation, the fish plates are preferrably plastic withsimulated bolts and nuts molded as a part of each fish plate. Eachmolded bolt (see FIG. 2C) is a nub 38 molded on the fish plate andsnapfits through holes 58 in a matching fish plate on the other side ofthe rail.

In FIG. 1, nubs (not shown) from the opposite-side fish plate passthrough holes in rails 10 and 18 and snapfit through holes 26 in fishplate 20. False nuts 24 are molded into fish plate 20 to simulate realnuts. Of course, in a conventional rail system, the fish plates wouldhave holes at the locations of false nuts 24 for normal nut/boltfastening of two abutting rails. The continuous conductive member orrail 16 is attached to both rails 10 and 18 by inserting the dovetailbead 14 into matching dovetail groove 12 in the rails. The flat portionof conductive rail 16 rests on the top surface of support rails 10 and18. The bead 14 of rail 16 riding in groove 12 holds the conductive railin place. Thus conductive rail 16 spans the support rail abutment joint22 so that relative to a vehicle or electro-motive device riding on therail there is no physical discontinuity or electrical discontinuity ofthe composite minimum-joint conductive rail at joint 22.

The minimum-joint conductive rail 16 terminates at some point along thetrack where it is desireable to end an electrical control zone. In FIG.1, rail 16 terminates where it abuts against floating insulator 28.Insulator 28 thus defines the end of one electric control zone orcontrol block defined by conductive rail 16 and the beginning of thenext control block defined by conductive rail 30.

Floating insulator 28 has a dovetail bead 32 to engage groove 12 in thesupport rail in the same manner as conductive rail 16. Insulator 28 andconductive rail 16 float on support rail 18 in that they may slide alongthe top of rail 18. This allows for expansion and contraction of theconductive rails due to changes in temperature.

FIGS. 2A and 2B show an alternative design for the plastic fish plates.Fish plates 34 and 35 are concave relative to the support rail 44 sothat a cavity 36 is formed between plates 34 and 35 and thenon-conductive support rails.

As illustrated in end view in FIG. 2B, nub 39 of shaft 38 is pressedthrough a hole in the fish plate by deforming the fish plates 34 and 35inward as depicted by arrows 33. Fish plates 34 and 35 are identical;when installed, plate 35 is reversed in direction relative to plate 34.Thus, shafts 38 of one plate extend through holes 58 (FIG. 2C) of theother plate. After nub 39 on shaft 38 of fish plate 34 has snappedthrough the hole in fish plate 35, plates 34 and 35 are held deformedtoward the support rail 44. As a result, plates 34 and 35 want to extendin an upward and downward direction, as depicted by arrows 42, againstthe foot 46 and head 48 of rail 44. The upward pressure on head 48 ofthe support rail causes the walls of groove 50 to pinch or grip thedovetail 52 of the conductive rail 54 mounted on the support rail.

FIG. 2C shows details of the fish plate or bracket 34. Shafts 38 andnuts 40 are molded as a part of plate 34. The position of the innermostedge of the concave inner surface of plate 34 is illustrated by dashedline 56. Holes 58 in the plate are tapered to receive the nubs 39 ofshafts 38 that snapfit into holes 58. The molded shape of nuts 40 is amatter of choice since they are provided for aesthetics in simulatingthe appearance of conventional track installation.

FIG. 3A illustrates a clip 64 for holding the support rail to a supportmember or railroad tie 62. Alternatively, the clip could hold thesupport rail directly to the roadbed. Clip 64 has spring tension arms60. A support rail may be snapped into the clip between the arms 64 asshown in FIG. 3B and be held by the clip on tie 62 or a roadbed (notshown).

FIG. 3B shows a non-conductive support rail 65 and minimum-jointconductive member 67 similar to rail 16 in FIG. 1. In addition FIG. 3Bshows a second conductive strip 69 (shown in end view at the end of therail) positioned at the bottom of support rail 65. One or moreconductive strips 69 might be used to conduct control signals, such as aradio frequency control signals, down the length of the track.Conductive strip 69 would be a continuous or minimum-joint strip in thesame manner as conductive strip 67.

A end view of support rail 65 with conductors 67 and 69 is shown in FIG.4A. In addition in FIG. 4A, the support rail 65 is made of a conductivemetal such as steel, brass, aluminum or tin. In this embodiment with aconductive support rail, there must be an insulating layer 67A and 69Abetween the support rail 65 and conductors 67 and 69 respectively.Insulating layers 67A and 69A are preferrably coatings of polycarbonatematerials. Plastics such as Vinyl or Teflon might be used.

Also shown in the end view in FIG. 4A is a space between the bottom ofconductor 67 and the bottom of the dovetail groove. This space isprovided so that a electrical wire might be trapped in the space afterpassing through a hole (not shown) in the support rail. Thus theconductor 67 can receive electrical power from a power source.

A preferred embodiment of the rail clip 64 is shown in FIGS. 4A, 4B and4C. Clip 64 is precast or molded out of flexible polycarbonate materialsand has posts 68 with ears 63 that snap fit over the base 46 of supportrail 44.

In the detail of FIG. 4B, the clip 64 has upstanding posts 68 molded asa single piece with base 65. Upstanding posts 68 have arcuate,vertical-fluted surfaces 66 and ears 63 to hold a rail firmly in placeafter it is snapped into clip 64. Fluted surfaces 66 would be shaped outof a harder material than the plastic clip and for example might be ametal insert such as steel, brass, or aluminum, molded into the clip.Further the rail base is held in a recessed area 67.

In FIG. 4C, there is a top view of clip 64 in FIG. 4B. Four posts 68 areshown. Arcuate fluted surfaces 66 are shown by dashed lines. The edges67A of recess 67 are indicated. Also holes 61 in base plate 65 areprovided so that the clip 64 can be fastened to railroad ties or roadbedwith nails, spikes or bolts through the holes.

When a rail is pushed down into clip 64, base 65 and posts 68 flex toallow posts 68 to open sufficiently for the base of the rail to slippast ears 63. After ears 63 snap over the base of the rail, the rail iskept from moving vertically and is held in recess 67 by ears 63 applyingretentive forces in direction of arrows 63A. In addition the rail iskept from slipping transverse to the direction of the rail by the edgesof recess 67 and by retentive forces (in the direction of arrows 66A)from the inner arcuate surfaces 66 of posts 68. The rail is kept fromslipping along the length of the rail by the vertical fluted surfaces66.

FIGS. 5 through 7 illustrate various alternative embodiments forattaching the minimum-joint conductive strip on top of the nonconductivesectional support rail. In FIG. 5, the conductive strip 71 has tworounded beads 70 and 72 for engaging rounded grooves 74 and 76respectively in non-conductive support rail 69.

In FIG. 6, the support rail 79 has a top surface containing acylindrical groove 80 with ears 82 and 83. The minimum-joint conductor84 has a cylindrical cross-sectional shape. When the conductor 84 ispressed into groove 80, ears 82 and 83 of the groove snap over theconductor. Conductor 84 has a diameter somewhat greater than the depthof groove 80 so that upto 20% of the diameter of the conductor protrudesabove the surface of the support rail. This will insure good electricalcontact between the conductive strip and wheels electro-motive devicedrawing power from the rail.

In FIG. 7, the support rail 87 has two dovetail grooves 88 and 90 toengage two conductive strips 92 and 94 respectively. Strips 92 and 94each have a dovetail bead 96 and 98 for engaging dovetail grooves 88 and90. Strips 92 and 94 are insulated from each other by a ridge 100 on thetop of the non-conductive support rail 87.

In FIG. 8, an alternative embodiment of the minimum-joint conductiverail is shown. In this embodiment, the dovetail bead 102 isdiscontinuous. The bead need not extend the length of the conductivestrip. There only needs to be a bead at spaced intervals. Two beads 102and 104 are shown. The interval between beads should be short enough sothat good engagement with the support rail is maintained when theconductive rail is snapped into the matching groove in thenon-conductive support rail.

FIGS. 9 and 10 illustrate attachment of minimum-joint conductive stripsto sectional non-conductive mono-rails. As in FIG. 1 the non-conductivemono-rail would be built of strong relatively stiff material to supportthe weight of the vehicle travelling on the rail. Accordingly, themono-rail would be in sections which would be assembled to form a track.The conductive strips would be flexible and of any length and would spanany number of mono-rail sections thereby providing electrical continuityfor a predetermined length of track.

In the mono-rail illustrated as an end view in FIG. 9, the rail issupported at the base 108 by pylons or a roadbed in cross- section. Theelectro-motive vehicle rides on the top surface 110 of the rail andcarries two electrical conductive wipers or wheels which make contactwith conductive strips 112 and 114. The continuous conductive stripshave a dovetail bead 116 and snap into a matching dovetail groove 118.

In the mono-rail illustrated as an end view in FIG. 10, the rail issupported at the top 120 of the I-beam by hanging support 122 incross-section. The electro-motive vehicle rides on wheels running on thetop surfaces 124 and 126 of the base 128 of the I-beam. The vehicle alsocarries two electrical conductive wipers or wheels which make contactwith conductive strips 130 and 132. The continuous conductive stripshave a dovetail shape and snap into a matching dovetail grooves 131 and133 respectively.

While a number of preferred embodiments of the invention have been shownand described, it will be appreciated by one skilled in the art, that anumber of further variations or modifications may be made withoutdeparting from the spirit and scope of my invention.

What is claimed is:
 1. A composite minimum-joint conductive rail forsupplying electrical power to an electro-motive device riding on thecomposite rail, said composite rail comprising:a plurality ofnon-conductive support rails; means for joining multiple support railsin end-to-end abutment to form a track of any length having multipleabutted joints; a continuous conductive rail member for conductingelectrical power along the support rails and across the multiple abuttedjoints of said support rails, said conductive rail member having alength independent of the positions of the abutted joints of saidsupport rails; each of said support rails having a support surface forslideably engaging and supporting said conductive rail member, wherebysaid continuous conductive rail member slides relative to said supportsurface as said conductor rail member expands or contracts, and wherebywhen the electromotive device rides on the composite rail, theelectromotive device is supported by the support rails and drawselectrical power from the continuous conductive rail member.
 2. Thecomposite rail of claim 1 whereinsaid support surface has across-section shape designed to mate with a cross-sectional shape of theconductive rail member, said support surface receiving and guiding thecontinuous conductive rail member across a plurality of abuttednon-conductive support rails.
 3. The composite rail of claim 2 whereinthe cross-sectional shape of said support surface is a dovetail groove.4. The composite rail of claim 2 wherein the cross-sectional shape ofsaid support surface is a groove shaped as the major chord of acylinder.
 5. The composite rail of claim 2 wherein said support surfacecontains multiple grooves.
 6. The composite rail of claim 1 wherein atleast a portion of said continuous conductive rail member is shaped formating with a portion of said support surface.
 7. The composite rail ofclaim 6 wherein:a body portion of the conductive rail member rests onsaid support surface of said non-conductive support rails; and a beadportion of the conductive rail member slideably engages the matingportion of said support surface of said non-conductive rails.
 8. Thecomposite rail of claim 7 wherein said bead portion of said conductivemember is discontinuous.
 9. The composite rail of claim 1 wherein eachof said support rails has at least one dovetail groove in he surface ofsaid support rail running the length of said support rail for slideableengagement with a dovetail bead on the continuous conductive rail memberwhereby the conductive rail member is mounted on the non-conductivesupport rail.
 10. The composite rail of claim 1 wherein each of saidsupport rails has at least one cylindrical groove in the surface of saidsupport rail running the length of said support rail in which acylindrical bead on the continuous conductive rail member slideablyengages.
 11. The composite rail of claim 1 wherein:each of said supportrails has at least one cylindrical groove in the surface of said supportrail running the length of said support rail; and said continuousconductive rail member is a cylindrical conductor that fits in saidcylindrical groove and protrudes above the surface of the non-conductivesupport rail.
 12. The composite rail of claim 1 wherein each of saidsupport rails has beveled edges in a top surface thereof and lateralcounter-beveled edges of the continuous conductive rail member engagethe beveled edges of the support rails.
 13. The composite rail of claim1 wherein said composite rail is subdivided into more than oneelectrical control block and comprising:a plurality of said continuousconductive rail members, the length of each conductive rail membercorresponding to a portion of the track in an electrical control block;an insulative spacer rail member separating abutting conductive railmembers at the end of each control block, said spacer rail memberengaged and supported by the support rails in the same manner as theconductive rail members, the position of the spacer member along thetrack being independent of the abutted joints between the support rails.14. The composite rail of claim 1 and in addition:one or more additionalcontinuous conductive rail members for conducting power along thesupport rails and across multiple abutted joints of said support rails,said additional conductive rail members having a length independent ofthe position of the abutted joints of said support rails; each of saidsupport rails having an additional surface for slideably engaging andsupporting each of said additional conductive rail members whereby theelectromotive device rides on the composite rail, is supported by thesupport rails and draws electrical power from two or more continuousconductive rail members.